Research On Catalytic Properties Of Copper Complexes For C-C Bond Forming Reaction

It has attracted chemist widespread attention that looking for high efficiency, simple, cheap, economic and environmental green organic synthesis strategy under the concept of green chemistry advocated in recent years. The synthesis and catalytic properties of metal-organic complexes have become the study hotspot. This dissertation aims to study the application value of copper complexes as catalysts in C-C bond-forming reaction, explore the influence of reaction conditions on the catalytic performance, associate the relationship between catalytic activity and catalyst structure further, provide theoretical guidance for future work finally. Paper's main work is divided into four chapters:In the first chapter, the research background was concisely introduced by illustrating recent advances on copper complexes. In addition, the significance of the research topic and the research progress were described.In the second chapter, solvothermal reaction of 1,3,5-tris?tetrazol-5-yl?benzene?H₃BTT? and Cu?OAc?₂ generated a sodalite-type copper metal-organic framework [(Cu₄O_0.27Cl_0.733(H_0.5BTT)₈?H₂O?-12]·3Me OH·9DMF?1? in which O/Cl-centered square planar [Cu₄O]/ [Cu₄Cl] units are linked via BTT^3- ligands to form the anionic, porous 3D?3,8-connected? framework. Compared with related M-BTT MOFs, the absence of irremovable guest [M?DMF?6]2+ cations and partial replacement of ?₄-Cl with ?₄-O at the square Cu₄ cluster in 1 enhance the effective pore volume and the Lewis acidity of coordinatively unsaturated metal centers. Complex 1 can be dehydrated to form [(Cu₄O_0.27Cl_0.733(H_0.5BTT)₈] 1? with coordinatively unsaturated Cu₂+ centers. Open Cu?II? sites with stronger Lewis acidity led to 1? being an active, stable and reusable solvent free heterogeneous catalyst for C-C bond-forming reaction by cyanosilylation of carbonyl compounds and constructed a series of cyanohydrin compounds. The loading of 1 mol% of catalyst 1? was as low as one eleventh of that used in related Mn-BTT but gave as high as 96% conversion of benzaldehyde, indicating that the catalytic activity of Cu-BTT MOFs was significantly improved via post-modification.In the third chapter, choosing phenanthroline as ligand with cupric nitrate synthesized three-coordinate planar dinuclear complex [Cu₂?ophen?₂]?2? and mixed valence tetranuclear complex [Cu₄?ophen?₄?tp?]?3?. The ligands of complex 2 are observed in form of deprotonated 2-hydroxy-1,10-phenanthroline, indicating that adjacent phenanthroline hydroxylation happened during the synthetic process. Based on the existing literature, we speculated that it may have the ability to activate oxygen. In order to explore its catalytic activity, the homocoupling of arylboronic acids and Glaser coupling reaction via three-coordinate planar dinuclear Cu₂?ophen?₂ complex catalyzed were studied respectively. It's worth noting that the catalyst showed high selectivity towards biphenyls when the reaction was conducted in non-toxic green water as main solvent, which was significantly different from selectivity towards phenols in related Cu-catalysts. On this basis, [Cu₂?ophen?₂]?2? and [Cu₄?ophen?₄?tp?]?3? were applied to aerobic Glaser reaction, the high conversion?99%? could be successfully achieved adopting environment-friendly water as solvent at room temperature under air/O2 atmosphere and avoiding the need for any base. It's worth mentioning that mixed valence tetranuclear complex 3 served as a heterogenous catalyst due to poor solubility in common solvents and could be reusable five times with low loading and high catalytic activity.In the fourth chapter, a concise conclusion for this thesis work was summarized and an outlook of this research area was anticipated.